A typical forage harvester operating in matured crops growing in rows, such as corn or the like, includes a mobile base unit and a row crop header attached to the base unit for cutting, gathering, and conveying crop material rearwardly to the base unit. The base unit includes a forward generally rectangular inlet opening for receiving crop material being conveyed rearwardly, a feeding assembly spanning the width of the inlet opening to engage the conveyed crop material, and a crop processor including a rotating cutterhead for receiving crop material from the feeding assembly and chopping it into small pieces, which constitutes the end product that is transferred to a wagon for transport to a storage facility, such as a silo.
The header attachment is mounted on the front of the base unit and has a rear, generally centrally located discharge outlet in communication with the inlet opening on the base unit. As is well known, the stalks of the row crop being harvested are cut near the ground by a cutting assembly on the header attachment, after which the cut crop is gathered and delivered rearwardly through the central discharge outlet and into the feeding assembly on the base unit. During the time the crop material is being conveyed the stalks are manipulated by the gathering and feeding means in a manner such that the cut ends of the stalks of the crop material, or stalk butts, are presented first to the feeding assembly. Thus, the crop material is fed, stalk butts first, to the cutterhead by the feeding assembly, which commonly comprises one or more pairs feed rolls mounted transversely across the inlet of the base unit.
It is not uncommon for an operator of a forage harvester to be confronted with different spacing between the rows of standing crop as he moves from one field to another. Furthermore, non uniform row spacing may be encountered in the same field during successive passes due to adverse planting conditions, unreliable row spacing integrity of the planting apparatus, etc. Unless the operator somehow compensates for such differences the standing crops are not likely to be aligned properly with the header stalkways that guide the crop rearwardly in typical row crop attachments.
Various efforts have been made in the past to overcome this problem. For example, the areas between the leading portions of adjacent crop receiving elements have been enlarged and extended forwardly to engage and urge standing crops to the cutters regardless of row spacing. This type of apparatus tends to be ineffective under conditions' where there are wide variations between row spacing and is also undesirable due to the additional bulk.
Other attempts to solve the problem involve the utilization of units in which the crop passages are laterally adjustable, such as shown for exemplary purposes in U.S. Reissue Pat. No. Re. 31,063, issued Oct. 26, 1982 in the name of James g. Greiner et al, and U.S. Pat. No. 4,084,396, issued Apr. 18, 1978 in the name of David P. Fritz et al.
Another approach in the past has been to provide a row crop attachment that is not sensitive to the spacing of standing crop material regardless of distance between the rows. Examples of apparatus of this nature are shown in U.S. Pat. Nos. 4,622,804, issued Nov. 18, 1986 in the name of Bernard Krone et al, and No. 4,926,623, issued May 22, 1990 in the name of Josef Fiener. In Krone et al, a chain driven mechanism is operative transverse to the direction of travel to cut standing crop and convey it transversely to a chopping assembly. The Fiener patent discloses apparatus in which a pair of counter rotating cutting assemblies engage stalk-like crops independently of row spacing and employ opposing truncated cone members to guide the cut crop material rearwardly to a centrally located chopper.
U.S. Pat. Nos. 4,594,842, issued Jun. 17, 1986 in the name of Norbert Walters et al, and No. 5,237,804, issued Aug. 4, 1993 in the name of Alfred Bertling, are further examples of prior art forage harvester row crop attachments that are not sensitive to the spacing between the rows of standing crop being harvested. In these patents, assigned to a common assignee, pairs of counter rotating cutting assemblies operate in a manner similar to the above discussed Fiener patent. In the first instance the counter rotating cutting assemblies cooperate with opposed sloping conveyor drums, forward of processor feed rolls, while in the latter instance there are no means intermediate the cutting assemblies and the processor feed rolls.
These efforts in the past to solve the problem of providing forage harvester row crop attachment apparatus that accommodates randomly spaced crops, have either resulted in mechanisms that require time consuming and inconvenient mechanical adjustments or have yielded solutions fraught with difficulties spawned by complex endeavors to provide an acceptable solution.